CN213276713U

CN213276713U - RFID transponder

Info

Publication number: CN213276713U
Application number: CN202020849707.0U
Authority: CN
Inventors: 安蒂·瓦尔托宁
Original assignee: Smartrac Technology GmbH
Current assignee: Smartrac Technology GmbH
Priority date: 2019-05-22
Filing date: 2020-05-20
Publication date: 2021-05-25
Anticipated expiration: 2030-05-20
Also published as: DE202019102894U1

Abstract

An RFID transponder for use in-mold labeling, having an RFID device which is formed by an RFID chip (2) and an antenna (3) connected or coupled thereto, both of which are arranged on a flat substrate (4) which is bounded by edges and has a first side (5) and a second side (7), wherein the RFID device (2; 3; 4) is provided with a covering on the first side and/or on the second side, characterized in that the covering (6; 8) is formed by a polyolefin-based melt adhesive.

Description

RFID transponder

Technical Field

The utility model relates to a RFID transponder, especially be used for the RFID transponder who uses in the mark of in-mould sticking. The RFID transponder is based on an RFID device, which is composed of an RFID chip and an antenna connected to the RFID chip. The RFID chip and the antenna are both disposed on a planar substrate bounded by edges and having a first side and a second side. The RFID device is provided with a covering on the first side and/or the second side.

Background

So-called "in-mold labeling" is used, for example, in the packaging industry. Here, the label is inserted into an injection mold and is injected with the aid of a plastic back-injection mold (hingerspriven). Here, the plastic can be placed in a mold corresponding to the package. Thereby realizing that: the package is also securely attached to the label.

Increasingly, tags are provided with RFID devices or are constituted by such RFID devices.

Such RFID devices cannot be used directly, i.e. unprotected, for in-mold labeling, since high pressures and temperatures occur in the injection mold during the back-injection or encapsulation, which can lead to damage of the RFID device. The same problem occurs in the following cases: RFID devices are produced by means of injection molding methods, which are not part of the packaging at the same time, i.e. in all methods in which the RFID device is back-injected or coated by means of thermal methods or in combination with high pressure.

It is therefore known to provide RFID devices in covers that provide protection against negative environmental influences. The RFID label manufactured in this way can then be used not only in-mould labelling but also in the manufacture of RFID devices and the like.

US 2009/0033495a1 describes a shaped plastic article with an RFID label (in-mold label) and a method of in-mold labeling.

The substrate of the RFID device includes a first surface on which the chip and the antenna are located and a second surface. The primer is applied not only to the first surface, including the antenna and chip, but also to the second surface. Over the primer, a polymeric cover is applied to the surface.

In order to produce injection-molded parts provided with such in-mold labels, the RFID label is arranged in the interior of the injection mold close to the surface of the mold. For this purpose, an adhesive may be used in order to maintain the position of the label in the injection mould. In injection molding, a material is injected into a mold to form a molded plastic article.

An RFID tag for use as an in-mold label is known from US 2004/0094949a 1. An RFID device, which is comprised of an RFID chip and an antenna disposed on a substrate, has a first surface and a second surface in opposition. A first layer of heat activated adhesive is disposed on the first surface of the RFID device and a second layer of heat activated adhesive is disposed on the second surface. A surface layer comprising a polymer film is disposed on a surface of the first layer of heat activated adhesive opposite the first surface of the RFID device. The label is placed into the mold with the surface layer contacting the mold. The polymer is then shaped in the mold such that the second layer of heat activated adhesive (or the surface layer over the second layer of heat activated adhesive) adheres to the polymer. Thereby producing a tag that can be identified by means of an RFID reading device.

Thus, the RFID transponder can be constructed in a multilayer manner, wherein the layer facing the outside is composed of a polymer material.

During the injection molding process, RFID devices based on PET (polyethylene terephthalate) substrates do not provide good adhesion between traditional plastics (PP (polypropylene) or PE (polyethylene)) because PET cannot be mixed with these non-polar polymers. Furthermore, the PET substrate material may be damaged in high temperature injection molding processes, especially when these conventional plastic polymers are extruded directly onto the antenna.

To improve the adhesion, RFID tags are known with thermoplastic encapsulation. The package also enables protection during the molding process.

In any case, however, the construction of the multilayer requires a plurality of processing steps and a special injection mold, resulting in a large cost.

It is necessary to position and fix the known RFID tag in the injection mold. Various methods are known for this purpose.

In the case of back-injection, the RFID tag can be fixed and positioned on the mould surface by means of an adhesive. However, no protective layer is thereby formed on the label, since the label is merely back-sprayed. It is therefore necessary that the covering assumes the function of a protective layer. This may cause an increase in the cost in manufacturing the RFID tag. Furthermore, the provision of adhesive between the label and the mould surface requires an additional work step.

Another possibility for fixation is a vacuum method. The vacuum method effectively holds the RFID tag at the desired location during the molding process, but results in high tooling costs.

In contrast to the two methods described above, in which the RFID tag is only anti-injected, that is to say only partially introduced into the plastic item, the dual-mold method enables the tag to be completely introduced into the plastic item. However, there is also the problem of fixing the label in a preforming tool (Vor-Form), which is then introduced into the second tool.

SUMMERY OF THE UTILITY MODEL

It is therefore an object of the present invention to provide an RFID transponder with which the adhesion to the injection molding material is improved while protecting the RFID device and with which the production costs can be reduced.

This object is achieved by an RFID transponder, in particular for use in-mold labeling, having an RFID device which is formed by an RFID chip and an antenna connected or coupled to the RFID chip, both of which are arranged on a flat substrate which is bounded by edges and has a first side and a second side, wherein the RFID device is provided with a covering on the first side and/or the second side, wherein the covering is formed by a polyolefin-based melt adhesive. The following description shows a particular design of the transponder.

According to the utility model discloses a solution proposes that the cladding comprises polyolefin-based melting adhesive. On the one hand, the encapsulation provides sufficient protection against high temperatures and high pressures during the injection molding process, and on the other hand, the fixing of the RFID transponder in the injection molding tool can be achieved without the need for additional glue or expensive vacuum injection molding tools. Furthermore, the encapsulation allows the elimination of further protective layers and the associated additional coating processes.

The overmold may be comprised of a reactive melt adhesive.

Reactive polyolefin melt adhesives are based on polyolefins having thermoplastic characteristics. The reactive polyolefin melt adhesive reacts to form a crosslinked polymer when applied under atmospheric moisture or by heating to a temperature well above the processing temperature. The molten adhesive may be simply deposited on the RFID device by heating and subsequently cross-linked to form a durable covering. For the manufacture of RFID transponders, the thermoplastic properties of which are to be maintained for subsequent processing steps, it is necessary to avoid crosslinking up to these processing steps.

In a further embodiment, it is provided that the sheathing consists of a reactive moisture-curing melt adhesive.

The reactive groups in the melt adhesive have a very positive influence on the adhesion spectrum, since the adhesive can additionally form strong (covalent) chemical bonds with suitable reaction partners on the surface of the substrate and on the surface of the injection-molded material.

The melt adhesive can in particular be selected from the group of polyolefin-based melt adhesives which have the greatest adhesion between the injection molding materials, in particular PP and PE polymers, and the RFID substrate material, in particular PET or polyimide.

The melt adhesive can be made of a material that is transparent in the hardened state, in order to enable optical inspection.

The covering can be arranged not only on one side, that is to say on one side relative to the substrate, but also on both sides. However, the following conditions must be followed: the RFID chip and the antenna are protected against influences from the injection molding process by means of the encapsulation. Thus, for example, it is possible to provide the covering only on the first side of the substrate in the following cases: the chip and the antenna are arranged on this side. However, it is also possible to arrange the chip on the first side of the substrate and the antenna on the second side, wherein the antenna is then coupled to the chip. Then, a cladding is placed on both sides. In any case, however, the cladding may also be provided on both sides.

In one embodiment of the invention, it is therefore provided that the RFID chip and the antenna are arranged on a first side of the substrate, and the covering is arranged on the first side of the substrate as a layer covering the chip and the antenna.

In a further embodiment, the encapsulation can also be designed as a layer covering the first and second side, respectively also the chip and the antenna.

In the case where the overmold is configured as a layer disposed on both sides of the substrate, the overmold on the first side and the overmold on the second side may each laterally protrude beyond an edge of the substrate, thereby completing the encapsulation of the RFID device.

Drawings

The invention shall be explained in more detail below on the basis of examples.

Fig. 1 shows an exploded view of an RFID transponder according to the invention.

Detailed Description

Fig. 1 shows an RFID transponder 1 having an RFID device which is formed from an RFID chip 2, an antenna 3 and a substrate 4. The antenna 3 may be made of copper or aluminum, however this is not essential to the invention. The substrate 4 may be composed of PET or polyimide.

The RFID chip 2 and the antenna 3 are arranged on a first side 5 of the substrate 4.

The RFID chip 2 and the antenna 3 are covered by a first layer 6 on a first side 5 of a substrate 4 of reactive moisture-hardening melt adhesive. The second side 7 of the substrate 4 is provided with a second layer 8 of a moisture-hardening melt adhesive, which is also reactive. Whereby the coating is achieved by the

layers

6 and 8.

The two layers are applied in a specific processing form for the respective melt adhesive, that is to say in solid, liquid or molten form by means of corresponding injection devices, application devices or similar devices for hot glue coating.

However, the transponder can also be bonded to a pre-shaped mold in a two-mold process and completely injected into the plastic of the plastic part. In this case, it is also possible that no more moisture reaches the

layer

6 or 8, thereby stopping or strongly delaying the moisture-dependent hardening and thus simplifying further processing steps, such as marking or printing.

It is also possible to use thermally crosslinked melt adhesives for the two

layers

6 and 8. Here, layers 6 and 8 are applied at a temperature below the crosslinking temperature. As soon as the melt adhesive is required for crosslinking, the transponder 1 or the surrounding plastic part is heated to the crosslinking temperature and the covering consisting of the two

layers

6 and 8 hardens.

In this case, it is also possible to use the temperature increase occurring during the injection molding for achieving the desired thermal crosslinking.

List of reference numerals:

1 RFID transponder

2 RFID chip

3 aerial

4 base

5 first side of the substrate

6 first layer, coating

7 second side of the substrate

8 second layer, cladding.

Claims

1. RFID transponder having an RFID device which is formed by an RFID chip (2) and an antenna (3) connected or coupled thereto, both of which are arranged on a flat substrate (4) which is bounded by edges and has a first side (5) and a second side (7),

it is characterized in that the preparation method is characterized in that,

the RFID device is provided with a wrapping on the first side and/or the second side, wherein

The overmold is composed of a polyolefin-based melt adhesive.

2. The RFID transponder according to claim 1,

it is characterized in that the preparation method is characterized in that,

the RFID transponder is configured for use in-mold labeling.

3. The RFID transponder according to claim 1,

it is characterized in that the preparation method is characterized in that,

the overmold is composed of a reactive melt adhesive.

4. The RFID transponder according to claim 3,

it is characterized in that the preparation method is characterized in that,

the sheathing is made of a reactive moisture-curing melt adhesive.

5. RFID transponder according to one of the claims 1 to 4,

it is characterized in that the preparation method is characterized in that,

the melt adhesive is composed of a group of polyolefin-based melt adhesives having maximum adhesion with injection molding materials and with RFID base materials.

6. The RFID transponder according to claim 5,

it is characterized in that the preparation method is characterized in that,

the injection molding material is polypropylene or polyethylene.

7. The RFID transponder according to claim 5,

it is characterized in that the preparation method is characterized in that,

the RFID substrate material is polyethylene terephthalate or polyimide.

8. RFID transponder according to one of the claims 1 to 4,

it is characterized in that the preparation method is characterized in that,

the melt adhesive is made of a material that is transparent in the hardened state.

9. RFID transponder according to one of the claims 1 to 4,

it is characterized in that the preparation method is characterized in that,

the RFID chip and the antenna are arranged on a first side (5) of the substrate (4), and the cover is arranged on the first side (5) of the substrate (4) as a layer covering the RFID chip and the antenna.

10. RFID transponder according to one of the claims 1 to 4,

it is characterized in that the preparation method is characterized in that,

the cover is arranged as a layer covering the first side (5) and the second side (7), respectively also covering the RFID chip (2) and the antenna (3).

11. The RFID transponder according to claim 10,

it is characterized in that the preparation method is characterized in that,

the cladding of the first side (5) and the cladding of the second side (7) each project laterally beyond the edge of the substrate (4) and are connected to one another in the region of the lateral projection.